Microarray cDNA to identify inflammatory genes in nasal polyposis

Background: The objective of this study was to investigate the spectrum of inflammatory gene expression in patients with nasal polyposis. Methods: The cDNA microarray technique was used to identify gene expression in tissue samples from nasal polyps and adjacent inflammatory nasal mucosa of 21 patients with nonallergic nasal polyposis. To validate the microarray analysis, we compared the expression of five genes by reverse transcription-polymerase chain reaction (RT-PCR): tumor necrosis factor, IL-5, IL-9, fibroblast growth factor, and transforming growth factor (TGF)-beta 1. Results: We tested 96 different inflammatory genes in our samples. Thirty-six genes exhibited differences in expression between the two tissue types. In all 36 genes the level of expression was greater in the inflammatory mucosa than the polyps. The RT-PCR confirmed the cDNA results. Conclusion: We believe that the high expression of TGF-beta 1 in inflammatory mucosa compared with the low expression in polyps may reflect an important role in the inhibitory mechanisms of nasal polyposis.